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Way to change all CV inputs from log to linear?

Is this possible? I find it a little tricky modulating a parameter by hand and even with offsetting.
Is there a setting in globals or am I missing something obvious?

The CV inputs (ABCDx) are all linear. :thinking:

However, some unit parameters respond linearly and some respond logarithmically and yet others exponentially. Something seems weird about the request, so could I have a specific example please?

No not the CV inputs on ABCD, i mean the unit parameter. Its the unit parameters particular I’m referring to. I want the option to change - between log / lin and expo (i forgot expo in the title) - mostly i want some of these expo and log curves changed to linear so i can smoothly cv a parameter. For example the delays, the eq, the reverb parameter’s At the moment when i cv or by hand you get a bit just on the bottom and minor changes on the upper part. Bias and gain will only get you so far because of the underlying curve on the CV parameter. I want a smooth transition over the whole range linearly.

Please tell me exactly what parameters you are referring to.

Careful with the use of the word “linearly”! I will get confused :wink: From the context of your post, I’m thinking that you want a curve that matches human perception which by the way is hardly ever linear. That’s why we use exponential curves for frequency and log curves for loudness.

no not at all - just to be clear, i mean a straight line from bottom left to to top right on an equal squared symmetrical, equal spaced grid :slight_smile:

Like what? Specifics please! I’m still lost as to your motivation. :upside_down_face:

Delay feedback is one - when i’m CVing that by hand in a live situation - and sweep from top to bottom, the bottom third jumps because of the (i guessing) log or expo curve? - i don’t want that to happen. EQ3 does the same. When you get up to the top it slows down. fO on the ladder filter is another - i want a smooth sweep not an expo sweep :slight_smile:

Those all have linear response curves already. Only the display is rendered in log or exp and adjustments to the bias via the encoder are also using the log or exp curves.

The f0 parameter is for linear FM. If you want exp FM then use the V/oct parameter.

Thanks - I see, that interesting and a little confusing. So you send a linear CV externally, it behaves as a linear CV internally, but visually shows you a log/exp render?
I thought the whole point of that display is to visualise what you are doing when cv’ing it externally.

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Here is a thought experiment for you: Let’s take f0 which by definition has to have a linear response curve in order to do linear FM. Now imagine that the f0 fader showed frequency in a linear fashion and you decide to modulate it with a sine wave from 180Hz to 240Hz. What will you see on the fader? (Keep in mind that the range is 0Hz to 13kHz.)


almost nothing :smiley:
the same reason why all spectrum analyzers visualize frequencies with an exponential distribution. if it was linear you’d see all the bass range, mid range and lower to mid high range compressed on the left side of the display. imagine having the center of the spectrum analyzer at 10khz :slight_smile:

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Ok gotcha - thanks for the explanation and also @hyena :slight_smile:


Hey, I’m still struggling to understand this issue as I have the same problem with the Ladder LPF cutoff control from linear voltage source (-5V to +5V). If I assign A1 to the Q, and then put 1.000 as gain and 0.5 as bias, I get a very beautiful and consistent range from top to bottom (not under!!!) of the numeric value (and the fader visualisation, but it’s obviously log or exp with cutoff) to it when I twiddle the voltage source knob. So can you guys help me out a bit, what are the magic numbers to get similar results from the cutoff parameter (for gain and bias of input that is)? I tried with my Maths’ channel 3 (-10V to +10V) and 10000 gain with it split by two to the cutoff (6,645 bias) seems almost good, but the bottom seems to cut out too fast, so like 1/5th of the knob is out of use at all because it’s somewhere in the abyss where I can’t see it, and when it is back it jumps almost like hitting a wall. I thank you wholeheartedly for all the answers you give in advance.

OH! I tried a bit out with my stuff and found out that when nothing is controlling the cutoff and you roll the encoder, the curve which the cutoff is controlled with seems very natural and sounds perfect! How can I achieve the same result with my ±5V voltage source?

Hopefully this rambling makes even a bit of sense…

The short answer is to use the V/oct input because your statement here:

strongly indicates that you do not want a linear frequency response. The V/oct input on the other hand will have an exponential response which is more natural to the human ear.

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Awesome, this is exactly what I’m looking for! Thank you very much!

I’ve read the thread, but I don’t know if I understand it correctly.

If you want to create a log curve with CV input.
Can I just use the V/OCT to Seconds unit?


Maybe. What are you modulating?

The length of the envelope to be sent to the VCA.

Well that unit will give you exponential control over a time duration. The base time, p0, will double for every 1V increase in the input. That is the meaning of V/Oct since octave means doubling.

As a formula,

OUTPUT = p0 * (2 ^ (10*INPUT))

im looking to change the cv in on @Joe 's Bespoke BPF Q and BW parameters to linear.
they seem to be log right now, which is unfortunate because there’s some real sweet spots in the lower ranges which are really hard to dial in when using external cv to control.
what’s the best way to go about this?
trying to create a 12 band filterbank so the less extra units i have to use the better…

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